export default /* glsl */ `
varying vec2 uv2;
uniform vec2 ratio;
uniform vec4 slashColor;
uniform float density; // 值越大 越稀疏

  void main() {
    vec2 pos = uv2 * ratio;
    float val = abs(pos.y - pos.x);
    val = mod(val, density);
    val = smoothstep(0.1, 0.0, val);
    vec4 lineColor = val * slashColor;
    gl_FragColor = lineColor;
  }
    `;
